<u># 用法</u>
<em>获取裁剪区</em>
<u># 语法</u>
<em>renderer</em>.<b>getScissor</b>( <s>target</s> )
<u># 参数</u>
<s>target</s> ：<em>必需</em>（<u>Vector2、Vector3、Vector4</u>）
<u># 示例</u>
<em>const Vector2</em> = <em><q>renderer</em>.<b>getScissor</b>(<s>new Three.Vector2( )</s>) 	<em>// => Vector2 { x: 0, y: 0 }</em>
<em>const Vector3</em> = <em><q>renderer</em>.<b>getScissor</b>(<s>new Three.Vector3( )</s>) 	<em>// => Vector3 { x: 0, y: 0, z: 1920 }</em>
<em>const Vector4</em> = <em><q>renderer</em>.<b>getScissor</b>(<s>new Three.Vector4( )</s>) 	<em>// => Vector4 { x: 0, y: 0, z:1920, w:427 }</em>